Multi-layer odor barrier tube, and combination odor barrier tube and odor barrier collection bag

REFERENCE TO RELATED APPLICATIONS

p-0002This application claims the benefit of the filing date of U.S. Provisional Application No. 60/976,214, filed Sep. 28, 2007.

FIELD OF THE DISCLOSURE

p-0003This disclosure is generally directed to medical tubing and, more specifically, to multi-layered tubing having odor barrier properties suitable for use as catheter tubing for fecal drainage systems, and a combination odor barrier tube and odor barrier collection bag.

BACKGROUND

p-0004Catheter tubes for fecal drainage systems are designed to facilitate flow of fecal matter, with the fecal matter typically draining into a collection bag. A catheter tube can include a lubricious coating on an interior to facilitate movement of fecal matter. While various materials have been used to form the walls of a catheter tube, no catheter tubes for fecal drainage systems are known that include integral odor barrier properties. One reason for the lack of catheter tubes having odor barrier properties is that odor barrier materials are understood to be too stiff and not suitable for catheter tubing applications. By providing a multi-layer catheter tube with at least one odor barrier layer, the catheter tube can reduce or eliminate exposure of the patient, caregivers, and other persons in the vicinity of the patient to unpleasant odors.

p-0005Fecal drainage systems are frequently employed in combination with enema, lavage, or other irrigation techniques to loosen stool in the rectum of a patient. As a result, water or other liquid is likely to travel through the catheter tube with fecal matter.

SUMMARY OF THE DISCLOSURE

p-0006In preferred embodiments of the present disclosure, the catheter tubing for a fecal drainage system is made of at least two layers of different materials. The layers are preferably co-extruded, or one layer may be extruded and one or more subsequent layers may subsequently be applied by extrusion over the first layer, but alternately, the layers may be formed as a generally flat laminate sheet that is rolled into a tubular shape, then sealed along a seam, for example using sealing technology, such as heat sealing or RF sealing, using adhesive sealing, or ultrasonic welding. In order to increase durability, at least one of the layers of the flat laminate sheet that is then rolled into a cylinder can be a semi-rigid mesh or scrim material.

p-0007Another desirable feature of a catheter tube for a fecal drainage system is minimal wall thickness. The multi-layer odor barrier catheter tube of the present disclosure can be manufactured with a total wall thickness in the range of about 10 mil to about 60 mil.

p-0008The odor barrier layer may be a resin, preferably a polyamide, and most preferably nylon <b>666</b>. The odor barrier layer may include an additive in the form of a modifier for reduced modulus, preferably ethylene-ethylacrylate-maleic anhydride terpolymer (commercially available as Lotader® 4720, from Arkema, Inc. of Philadelphia, Pa.). The odor barrier layer is preferably the outermost layer, or outer skin, of the catheter tube.

p-0009The odor barrier layer of the catheter tube preferably has a thickness of 3 mil or less, and the thickness of the odor barrier is preferably less than 30% of the total tube wall thickness. The odor barrier layer preferably has a kinetic coefficient of friction less than 0.5.

p-0010A second layer of the catheter tube may be a resin or resin blend, preferably having a modulus of elasticity less than 100,000 psi (2% secant) when measured according to ASTM D882.

p-0011A third layer forming the innermost layer or inner skin of the catheter tube may also be employed. The third or innermost layer preferably has a low kinetic coefficient of friction, preferably less than 0.5. The low kinetic coefficient of friction may be an inherent property of a dry material of which the third layer is formed. Lubricity is a beneficial feature of the innermost layer of the catheter tube to promote or facilitate flow of fecal matter through the catheter tube. In order to achieve the desired lubricity of the innermost surface of the catheter tube, the inner layer of the multi-layer odor barrier tube of the present disclosure may be made of a copolymer of ethylene, preferably an ethylene vinylacetate copolymer (EVA) with an added slip agent concentrate, such as 10090 Slip PE MB, having a concentration of 5% Erucamide, available from Ampacet of Tarrytown, N.Y., to lower the coefficient of friction. Preferably, the slip agent concentrate is only about 2% of the overall composition of the innermost layer of the catheter tube, so the effective concentration of the Erucamide is about 0.1%.

p-0012In light of the likely presence of water or other liquid traveling through the catheter tube with the fecal matter, as an alternative to an EVA copolymer, a hydrophilic polymer that becomes lubricious in contact with water, preferably polyethyleneoxide or polyvinylalcohol, may be used as the inner layer of the multi-layer odor barrier catheter tube.

p-0013If the collection bag into which the catheter tube drains lacks odor barrier properties, unpleasant odors can escape the collection bag, thereby negating the odor barrier benefits achieved by the odor barrier catheter tube. It is therefore desirable for the odor barrier tube to drain into a collection bag that itself has odor barrier walls.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

p-0014<figref idrefs="DRAWINGS">FIG. 1</figref> is a perspective view of a first embodiment of a multi-layer odor barrier catheter tube of the present disclosure;

p-0015<figref idrefs="DRAWINGS">FIG. 2</figref> is an axial cross-sectional view, taken along lines <b>2</b>-<b>2</b> of <figref idrefs="DRAWINGS">FIG. 1</figref>;

p-0016<figref idrefs="DRAWINGS">FIG. 3</figref> is an axial cross-sectional view, similar to <figref idrefs="DRAWINGS">FIG. 2</figref>, of a second embodiment of a multi-layer odor barrier catheter tube of the present disclosure, wherein tie layers are provided between the first and second layers, and between the third and fourth layers;

p-0017<figref idrefs="DRAWINGS">FIG. 4</figref> is a perspective view of a heat-laminated film employed in a method of manufacture of a multi-layer odor barrier catheter tube of the present disclosure;

p-0018<figref idrefs="DRAWINGS">FIG. 5</figref> is a perspective view of the heat-laminated film of <figref idrefs="DRAWINGS">FIG. 4</figref>, rolled into a cylindrical shape and sealed along a seam;

p-0019<figref idrefs="DRAWINGS">FIG. 6</figref> is a perspective view of a heat-laminated film similar to that of <figref idrefs="DRAWINGS">FIG. 4</figref>, and including a flexible scrim layer;

p-0020<figref idrefs="DRAWINGS">FIG. 7</figref> is a perspective view of the heat-laminated film of <figref idrefs="DRAWINGS">FIG. 6</figref>, rolled into a cylindrical shape and sealed along a seam;

p-0021<figref idrefs="DRAWINGS">FIG. 8</figref> is a front view of a combination of a multi-layer odor barrier catheter tube of the present disclosure in combination with a drainable collection bag having odor barrier walls;

p-0022<figref idrefs="DRAWINGS">FIG. 9</figref> is a front perspective view of a combination of a multi-layer odor barrier catheter tube of the present disclosure in combination with a closed, single-use collection bag having odor barrier walls; and

p-0023<figref idrefs="DRAWINGS">FIG. 10</figref> is a front perspective view of a multi-layer odor barrier catheter tube of the present disclosure having only two layers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

p-0024With reference to the drawings, in a first embodiment of a multi-layer odor barrier catheter tube <b>10</b> of the present disclosure connectable at a first end to a patient-proximal internal section, and/or a trans-anal section of a rectal catheter (not shown), and at a second end, connectable to a waste collection bag or to a disposal receptacle (e.g., a bedpan or toilet (not shown)) is provided. At least one of the layers of the multi-layer catheter tube <b>10</b> is constructed of materials resistant to transmission of fecal and flatus gasses.

p-0025A first layer <b>12</b> of the catheter tube <b>10</b> defines the external surface <b>14</b> of the catheter tube <b>10</b>. The first layer <b>12</b> is preferably comprised of one or more materials that possess a relatively low coefficient of friction, most preferably less than 0.5, so as to reduce drag of the catheter tube <b>10</b> against a patient's skin, and against items surrounding the patient, including a hospital gown, bed sheets, chair or other objects in the patient's immediate vicinity. The low coefficient of friction of the external surface <b>14</b> of the catheter tube <b>10</b> also facilitates “milking” the fecal matter down the length of the catheter tube <b>10</b>. The material or materials defining the first layer <b>12</b> of the catheter tube <b>10</b> include an odor barrier resin. In other embodiments within the scope of the present disclosure, the odor barrier resin may be employed as a layer of the catheter tube <b>10</b> other than the first layer <b>12</b> defining the outside surface <b>14</b>.

p-0026A suitable material for the first layer <b>12</b> of the catheter tube <b>10</b> of the present disclosure is a polyamide, most preferably nylon 666. A modifier may be added to achieve a reduced modulus, preferably ethylene-ethylacrylate-maleic anhydride terpolymer, commercially available as Lotader® 4720 from Arkema, Inc. The external surface <b>14</b> of the first layer <b>12</b> is preferably a surface that will receive inks such as permanent or semi-permanent markers, and retain such markings thereon without smudging or wiping off, to facilitate receiving instructions, patient data, collection bag change data, dates of indwell or intended removal of the catheter tube, and the like.

p-0027An intermediate layer <b>16</b> of the multi-layer catheter tube <b>10</b> preferably comprises a resin or resin blend having a modulus of elasticity less than 100,000 psi (2% secant) when measured according to ASTM D882. The resin used as the material forming the intermediate layer <b>16</b> is preferably a thermoplastic elastomer, most preferably polyurethane or a polyurethane blended with another thermoplastic elastomer, having a preferred modulus less than 40,000 psi (2% secant). As described in more detail below, more than one layer of material may be provided intermediate the first layer <b>12</b> defining the external surface <b>14</b> of the catheter tube <b>10</b> and a third layer <b>18</b> defining an internal surface <b>20</b> of the catheter tube <b>10</b>. If only a first layer <b>12</b> and a low modulus layer are provided, the layer referenced herein as the intermediate layer <b>16</b> may instead be the inner-most layer of the catheter tube <b>10</b>, as shown in <figref idrefs="DRAWINGS">FIG. 10</figref>.

p-0028Depending on the compatibility of the materials of adjacent layers of the multi-layered catheter tube <b>10</b>, as shown in <figref idrefs="DRAWINGS">FIG. 3</figref>, a tie layer <b>22</b>, such as a Bynel® tie material available from DuPont, may be employed between adjacent layers to improve adhesion of the adjacent layers to one another.

p-0029Another layer <b>18</b> of the multi-layer catheter tube <b>10</b>, defining the internal surface <b>20</b> of the catheter tube <b>10</b>, is preferably made of one or more materials that possess a relatively low coefficient of friction, preferably less than 0.5, to allow stool and bowel discharge to flow easily along the internal length of the catheter tube <b>10</b> for collection and/or disposal. A suitable material for the layer <b>18</b> is a copolymer of ethylene, most preferably an ethylene-vinylacetate copolymer (EVA) with an added slip agent (such as 10090 Slip PE MB, having a concentration of 5% Erucamide, available from Ampacet of Tarrytown, N.Y.), wax, PTFE, or other friction-reducing additive to achieve a low coefficient of friction. Such additives may also be used to lower the coefficient of friction of the first layer <b>12</b> defining the external surface <b>14</b> of the catheter tube <b>10</b>. As an alternate to the material or materials defining the layer <b>18</b> of the catheter tube <b>10</b> inherently possessing a low coefficient of friction, a hydrophilic polymer that becomes lubricious in contact with water, preferably polyethyleneoxide or polyvinylalcohol, may be used as the innermost layer of the multi-layer odor barrier catheter tube <b>10</b>. This may be accomplished by the layer <b>18</b> having a capability of anchoring hydrophilic materials thereto, and then supplying an additional hydrophilic layer, such as by co-extrusion, internally of the layer <b>18</b>. As a further alternate, the layer <b>18</b> may itself be formed entirely of a hydrophilic polymer, and anchored directly to intermediate layer <b>16</b>, provided that there is adequate adhesion between the hydrophilic layer <b>18</b> and the intermediate layer <b>16</b>.

p-0030The multi-layer catheter tube <b>10</b> of the first embodiment of the present disclosure may be manufactured by co-extrusion. In order to maximize tube softness and flexibility, it is desirable for the odor barrier layer of the catheter tube <b>10</b> to be thin, preferably in a range of less than about 2 to about 3 mils.

p-0031As an alternative to co-extrusion, as shown in <figref idrefs="DRAWINGS">FIGS. 4-5</figref>, the layers of the catheter tube <b>10</b> may be formed into a flat or substantially flat heat-laminated film <b>24</b>, having two parallel edges <b>26</b>, <b>28</b> that are rolled toward one another, brought into register with one another, and sealed to one another, such as by heat sealing, RF sealing, adhesive sealing, or ultrasonic welding, to form a cylinder, with the first layer <b>12</b> of the film <b>24</b> defining an external surface <b>14</b> of the cylinder and the third layer <b>18</b> defining an internal surface <b>20</b> of the cylinder. A leading end <b>30</b> and a trailing end <b>32</b> of the heat-laminated film <b>24</b> are left open, forming first and second ends <b>34</b>, <b>36</b> of the catheter tube <b>10</b>. Optionally, tie layers (represented by broken lines in <figref idrefs="DRAWINGS">FIG. 4</figref>) may be provided to enhance bonding between the first and second layers, and/or between the second and third layers <b>16</b>, <b>18</b>. The first, second and third layers <b>12</b>, <b>16</b>, <b>18</b> of the catheter tube <b>10</b> are preferably clear or translucent. The sealed edge or seam <b>38</b> may be visible, and can advantageously provide a medical caregiver with a visible indicator of any kinking or twisting of the catheter tube.

p-0032The total cumulative wall thickness of the multi-layer catheter tube <b>10</b> is preferably in the range of about 10 mil to about 40 mil, and more preferably in a range of about 25 mil to about 35 mil, with the thickness of the odor barrier layer (e.g., the first layer <b>12</b>) making up less than about 30% of the total wall thickness of the catheter tube <b>10</b>.

p-0033Adjustments may be made to process conditions under which the layers of the multi-layer catheter tube of the present disclosure are co-extruded or heat laminated to reduce the coefficient of friction of one or more of the layers.

p-0034In another embodiment, shown in <figref idrefs="DRAWINGS">FIGS. 6-7</figref>, in order to provide reinforcement and avoid kinking or twisting of a catheter tube <b>40</b>, a mesh or flexible scrim layer <b>42</b> may be included as an additional layer intermediate the first layer <b>12</b> and third layer <b>18</b> of the multi-layer catheter tube <b>40</b>. The scrim layer <b>42</b> also provides the catheter tube <b>40</b> with shape memory, permitting the catheter tube <b>40</b> to collapse and recover to its cylindrical shape without any permanent deformation. Materials other than a scrim layer <b>42</b> may be utilized instead of or in addition to the scrim layer <b>42</b> to enhance structural integrity of the catheter tube <b>40</b>, such as polymeric materials.

p-0035The material(s) forming the internal and/or external surfaces of the multi-layer catheter tube of the present disclosure preferably facilitate attachment and assembly of the catheter tube to peripheral components of fecal drainage and management systems, such as the Bowel Management System available from Hollister Incorporated of Libertyville, Ill., the assignee of the present disclosure. As such systems are intended for long-duration use, on the order of about twenty-nine days, it is advantageous to employ materials that will easily form a reliable bond, by adhesive and/or heat, between the catheter tube and the peripheral components, such as internal or external silicone balloons, catheter connections, such as to a collection bag or to a catheter tube extension, or plastic or metal ports, such as ports for providing endoscope access or for sampling fecal matter directly from the catheter tube, for the entire duration of use of the catheter.

p-0036As noted above, the advantages achieved by the odor barrier properties of the catheter tubes of the present disclosure would be negated, or significantly diminished, if fecal or flatus gasses could be transmitted through one or more walls of a collection bag <b>44</b> (see <figref idrefs="DRAWINGS">FIG. 8</figref>) to which the catheter tube <b>10</b> is connected. It is therefore desirable to use the multi-layer odor barrier catheter tube <b>10</b> in combination with a collection bag <b>44</b> having odor barrier walls. For example, each of the walls of the collection bag may include a barrier layer film such as the one disclosed in U.S. Pat. No. 7,270,860.

p-0037The odor barrier collection bag may be a drainable collection bag <b>44</b>, having a drainage tube <b>46</b> with a drainage tube stopper <b>48</b> and a cap <b>50</b> for capping a catheter tube connection port <b>52</b>, as shown in <figref idrefs="DRAWINGS">FIG. 8</figref>. Alternately, the odor barrier collection bag may be a so-called “closed” collection bag <b>54</b>, as illustrated in <figref idrefs="DRAWINGS">FIG. 9</figref>. A closed collection bag <b>54</b> is intended for single use, and preferably includes an integral vent <b>56</b> with a deodorizing filter <b>58</b>.

p-0038While certain embodiments of multi-layer odor barrier catheter tubes, combinations of multi-layer odor barrier catheter tubes and odor barrier collection bags, and methods of manufacturing multi-layer odor barrier catheter tubes are disclosed herein, the appended claims are not intended to be limited thereto. Variations can be made to the disclosed embodiments that are still within the scope of the appended claims, literally or under the doctrine of equivalents.